Add missing requirements.txt for a quickstart (GoogleCloudPlatform#1751)

* Updated trampoline script to match latest version that cleans up files

* Added newline to end of trampoline script

* A quickstart test was missing requirements.txt

Author: engelke

appengine/standard/endpoints-frameworks-v2/quickstart/requirements.txt

@@ -0,0 +1,2 @@
+google-endpoints==4.5.0
+google-endpoints-api-management==1.9.1